1GB 256bit GTX 460 vs 768MB 192bit GTX 460 SE?

Solution
The 1GB GTX 460 is much better. Not only does the 768MB version obviously lose in VRAM, but the "SE" on the end of the 768MB version means it's underclocked for lower speed (and lower power consumption, but there are better cards for that now anyway). The higher bandwidth on the 1GB version will also allow it to scale up with antialiasing and higher resolutions without losing as much performance. The normal 1GB GTX 460 is overall the much stronger card.

I used to have a 768MB GTX 460 GC (factory overclocked, rather than underclocked), and I got rid of it about a year ago. If I had the 1GB version I wouldn't even have sold it yet, I'd still be using it.

Having said that, you should only buy either of them if you can get them for quite...
The 1GB GTX 460 is much better. Not only does the 768MB version obviously lose in VRAM, but the "SE" on the end of the 768MB version means it's underclocked for lower speed (and lower power consumption, but there are better cards for that now anyway). The higher bandwidth on the 1GB version will also allow it to scale up with antialiasing and higher resolutions without losing as much performance. The normal 1GB GTX 460 is overall the much stronger card.

I used to have a 768MB GTX 460 GC (factory overclocked, rather than underclocked), and I got rid of it about a year ago. If I had the 1GB version I wouldn't even have sold it yet, I'd still be using it.

Having said that, you should only buy either of them if you can get them for quite a low price. There are newer cards available, after all.
 
Solution
initially the 1GB version was supposed to be a bit faster than 786MB one. but there are many variant of 460 that got release by nvidia. but if you have to pick between the two i'd say take the one with 1GB of RAM. anyway are just choosing between existing card or buying a new card?